Theodosius I - Emperor of Rome: "After the Visigoths trounced the Eastern Empire and killed its emperor (Valens) at the Battle of Adrianople, the emperor of the west, Valens' nephew Gratian, sent his best general, Theodosius, east to restore the situation. Theodosius' own father had been a senior military officer in the Western Empire whom Valentinian made magister equitum praesentalis in 368 and then executed in early 375. At about the time Valentinian executed his father, Theodosius went into retirement in Spain, where he had been born in 346. It was only after Valentinian's death (November 17, 375) that Theodosius regained his commission. He fought the Sarmatians and obtained the rank of the magister militum per Illyricum in 376, which he kept until January 379 when Gratian appointed him co-Augustus to replace Valens who had lost the Battle at Adrianople the preceding August.
The Goths and their allies were ravaging not only Thrace, but also Macedonia and Dacia. It was Theodosius' job to suppress them while Gratian attended to matters in Gaul. Although Gratian provided some troops, Theodosius was in need of more - especially after the Adrianople devastation - so he recruited troops from among the barbarians. In an only partially successful attempt to stave off defections, Theodosius sent some of these new recruits to Egypt and had Roman soldiers sent to him as replacements. In 382 Theodosius and the Goths reached an agreement. Theodosius permitted the Visigoths to retain some autonomy while living in Thrace.
Many of the Goths enlisted in the imperial army, which was rebuilt with emphasis on its cavalry - the need for which had been learned at the disastrous Battle of Adrianople. In January of 383, Theodosius named his young son Arcadius successor. Maximus, a general who had served with Theodosius' father and may have been a blood relative, may have hoped to be named instead. That year Maximus' soldiers proclaimed him emperor and with them he entered Gaul to face Gratian who was betrayed by his own troops and killed in Lyons by Maximus' Gothic magister equitum. Maximus was preparing to advance on Rome when Gratian's brother, Valentinian II, sent a force to meet him. Maximus agreed to accept Valentinian II in 384, but in 387 he advanced again. This time Valentinian II fled to Theodosius who took his army west to fight Maximus in Illyricum at Emona, Siscia and Poetovio. Despite many of his Gothic troops defecting to Maximus' side, Maximus was captured and executed at Aquileia on August 28, 388. One of the defecting Gothic leaders was Alaric who fought for Theodosius in 394 against Eugenius, another pretender to the throne, and then against Theodosius' son."